What does it mean to react in a scientific sense?

In a scientific context, to react means to interact in such a way that a new substance is formed as a result of the interaction between two or more different substances. This process is often associated with chemical reactions, where reactants undergo a transformation through chemical bonds breaking and forming, leading to products that have different properties from the original substances.

This definition captures the essence of what it means to react scientifically, highlighting the creation of new materials, which is fundamental to many branches of science, including chemistry and biology. The other choices pertain to different scientific concepts but do not specifically define what it means to react. For example, remaining in a stable state refers to equilibrium conditions, conducting a secondary observation relates to experimental procedures, and applying theoretical knowledge refers to the use of scientific principles in practice rather than the act of reacting itself.